PRESIDEJfT S ADDRESS. 173 



to be 5-59 million on one bushel of 84 l])s. of coal. 



January 5. Watt's first patent. 

 1770. Suieaton made note of eigliteen large engines in Cornwall, 



eight of which had cylinders from 60 in. to 70 in. in 



diameter. 

 1772. Smeaton made improvements in details, not altering the 



general construction, and succeeded in obtaining a duty 



of 9-5 millions. 

 1776. Smeaton erected a Newcomen engme at Chacewater in 



Cornwall. The steam cylinder was 72 in. in diameter. 



Water load, 7f lbs. Lift of pumps, 360 ft. This engine 



was altered by Watt to his system. 



1776. Watt corresponded with Smeaton and claimed 21-6 



millions duty for his engines. Smeaton, after making 

 experiments with Watt's engines, laid it down as a 

 general rule that the Watt engines did double the duty 

 of the Newcomen. 



1777. Watt erected three more of his engines in Cornwall, his 



first having been erected the previous year. In these 

 engines the load on the piston was increased from the 

 8 lbs. in the Newcomen to 1 1 lbs. or 1 2 lbs. in the Watt 

 engines. 



1778. Smeaton found that a Watt engine at the Birmingham 



Canal did a duty of 18 millions, and one at the Hull 

 Water Works 18-5 millions. Two engines at Poldice 

 were fovmd to do a duty of 7 millions on one bushel of 

 coal. 

 1781. October 25. Watt's second patent. 

 1800. Watt finished his labour in Cornwall, having raised the 



duty of his engines to 20 millions. 



1810. A Newcomen engine was erected at the Farme Colliery, 



Eutherglen, Scotland, for winding and pumping ; in 



1820 another was added for winding, and in 1821 



another, having a 60 in. cylinder, for pumping. 



Newcomen had associated with him Cawley, a plumber and 



glazier, and it will be observed that the pipes of the engines 



were at first made of lead with plumber's joints. In the early 



days the steam- cylinders only were obtained from iron-founders 



